Topband: Band Open - But No Sunrise Peak
nhp at ieee.org
Fri Jan 12 19:48:27 EST 2018
Thanks for the clarification Dave. When did you last see consistent
SR peaks at your location?
I suspect that
http://www.swpc.noaa.gov/products/solar-cycle-progression shows the
source of our difficulties. The highest level of geomagnetic
activity in the present cycle started in late 2014. Up to that
point, high latitude conditions in this location seemed pretty
reasonable overall, considering the progress of the solar cycle, but
since then, they've been fairly poor overall.
Perhaps quieter geomagnetic conditions overall contribute to the
likelihood of the occurrence of sunrise peaks in signal
strength? (though that's difficult to tell if there are also no
signals heard previous to sunrise due to poor conditions)
At 21:30 2018-01-12, daraymond at iowatelecom.net wrote:
>When I refer to a SR peak in my earlier post, I'm referring to an
>increase in actual signal levels (with corresponding increase in S/N).
>73. . . Dave, W0FLS
>-----Original Message----- From: Nick Hall-Patch
>Sent: Friday, January 12, 2018 11:23 AM
>To: Petr Ourednik ; topband at contesting.com
>Subject: Re: Topband: Band Open - But No Sunrise Peak
>Wasn't some of the apparent peaking of signals at sunrise due to
>improved signal to noise levels as noise levels drop at sunrise?
>20 years ago for many of us, noise levels did actually drop at
>sunrise. For many DXers now, (man-made) noise levels stay the same
>after sunrise, so, no apparent increase in signal strength (actually
>increase in S/N ratio).
>This is not to say that there was no "real" increase in signal
>levels at sunrise 20 years ago, just that it was perhaps less
>frequent than was thought at the time. If someone has recorded
>signal strength levels from that period, I'd be happy to be proved wrong.
>This morning, in western Canada, a medium-wave broadcaster,
>HLAZ-1566kHz from South Korea was audible until after 1700UT, an
>hour past local sunrise, with a reasonable sunrise
>peak. Yesterday, there wasn't much of a sunrise peak, and local
>noise conditions haven't changed that much over 24 hours.
>Was any west coaster on 160m on those two mornings?
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